Ishmael - discussion points expanded

Humans have been living on this earth for over 3 million years, but when studying "human" history, we only focuses on the last 10,000 years. We seem to have a an unspoken agreement that nothing important happened during the first 99.7% of human history. Why is that?

"It was universally agreed that "human history" was basically the same as "our history" - the history that began about ten thousand years ago with the agricultural revolution." - Ishmael pg xi​

"In three million years of human life that came before that, nothing of importance had occurred (except perhaps the domestication of fire and the invention of the wheel). The lives lived during that time were of no interest or importance, were in fact completely meaningless, and undeserving of any attention." - Ishmael pg xi